1. They kiss mouth to mouth or to cheek as if it's nothing (casual kiss)
Yeah as other's have said probably just had this one lumped in.
2. They all have blonde hair and blue eyes.
My guess is this one got lumped in as well but I'm more or less clueless as to why its not even a "funny" or common stereotype.
3. They are all loud or obnoxious.
At times I find this hard to deny.
4. They are messy
We are kind of to blame for this with the whole messy kid/teen/men stereotype's they just took it a bit further.
5. They are exhibitionists (they don't care about being seen naked or what-not)
Ok, once again lumped in with a generally European stereotypes I'm starting to get insulted.
6. They all have guns and they all know how to use one.
Well we do have more gun's then citizens.

They can also be ridiculously over-the-top, and that can include their weapon usage.

Dan Eagleman in Guilty Crown isn't a bad example.

All I can say is at least he died a somewhat heroic death, I was expecting a lot worse from him after seeing some far worse one's, such as the American from Neuro who, while played to the extreme for comedy was still serious enough to put some people I know off the show.

Also how have we gotten this far without mentioning my personal favorite Chibodee Crocket

If you look hard enough you'll find a Japan citizen has made a Japanese manga about French kissing tradition infused with Japan (home) lifestyle... The French have a five kiss greeting I think... It's all about the creator's interest.

In an anime called Hetalia, there is a character called America lol. He loves hamburgers and he calls himself a hero. I got some of this from Wikipedia.

Well Hetalia did it to all nation though, its just easier to make fun of America lol .. but I do love the Burger , Fries and Shake associated to him ha ha h and everytime Konishi san does this character , he has a funny grin in his face lol a.

In an anime called Hetalia, there is a character called America lol. He loves hamburgers and he calls himself a hero. I got some of this from Wikipedia.

Well Hetalia did it to all nation though, its just easier to make fun of America lol .. but I do love the Burger , Fries and Shake associated to him ha ha h and everytime Konishi san does this character , he has a funny grin in his face lol a.

Don't forget that they are tall, have "deep" voices, are aggressive, the women are slutty and have "big" boobies, the men are muscular, and we all wear sunglasses. And of course hamburgers, even though it's pretty hip to be vegetarian.

I don't know about the kissing thing, it seems more like we think that's gross unless you're doing that with your hubby/girlfriend. We just consider that a European thing.

At the beginning I thought Sentaro was portrayed as a typical American anime character, so when they revealed that he was half American I wasn't surprised at all.

But yeah, it is kind of interesting how they portray us. It could be a lot worse considering our history. -_-;

And to be honest a lot of it isn't inaccurate, even if it is stereotyping a bit.

It's a stereotype for a reason. I personally have seen some jaw-droppingly bad behavior more than once when I was traveling in Europe. To be fair, citizens of other countries do stupid crap too. The only difference is that Americans tend to call attention to the fact that they are Americans.